Percussion drilling apparatus



Dec. 12, 1961 R. P. VINCENT EI'AL 3,012,540

PERCUSSION DRILLING APPARATUS Filed Jan. 20, 1960 RENIC P VINCENT LAWRENCE B. WILDER INVENTORS 89 m 4 l 4 4 B 5 l a 3 kw m u u w M5 4. 5 \HIII N\\\\\-\\ QN II M x m% v A p w 2 5 g E 5 I I I W W l A I I /w v \E CW Y I I 5 a AAA? 4??? \s I 4 I W B N. 8 w a W 7 I W1 2 4 5 ATTORNEY I percussion drilling apparatus.

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United States Patent 3,012,540 PERCUSSION DRILLING APPARATUS Renic P. Vincent and Lawrence B. Wilder, Tulsa, Okla., assignors to Pan American Petroleum Corporation, Tulsa, Okla., a corporation of Delaware Filed Jan. 20, 1960, Ser. No. 3,656 8 Claims. (Cl. 121-28) This invention relates to an improved fluid actuated More particularly, this invention relates to a rotary drilling apparatus having a fluid actuated percussion motor attached near the drill bit for supplying percussive blows to the bit during drilling. Various types of rotary-percussion drilling tools, wherein the drill bit is rotated by the drill pipe and a supplementary longitudinal vibration is applied to the bit during rotation, have been developed to increase the rotary drilling rate. An apparatus of this type is shown, for

example, in US. Patent 2,859,733 to Bassinger et al. This invention relates specifically to an improvement in such apparatus.

It is an object of this invention to provide an improvematic actuated rotary percussion drilling apparatus shown and described in the above-mentioned Bassinger et al.

Other objects of this invention will become apwill be made to the accompanying drawing. This drawing shows a cross-sectional view of a preferred embodiment of a rotary percussion drilling apparatus.

In brief, this invention comprises an improved rotarypercussion drilling apparatus in which a vibratory motor is protected from contaminants or impurities such as water and solids in the drilling fluid by separating them out before they enter the vibratory motor or otherwise preventing them from backing up with the drilling fluid into the vibratory motor.

Reference will now be made to the accompanying drawing for a more detailed description of a preferred ern- The drilling apparatus at drilling rig and drilling fluid compressors for rotating the drill pipe 10 and circulating drilling fluid through a vibratory motor such as the percussion motor 11 and through drill bit 12, both of which are located below the surface in a well. A drill pipe float valve which is merely a unidirectional valve such as a check valve 13, is located between the drill pipe and percussion motor preferably adjacent to or in the fluid inlet 14 to the percussion motor.

This valve forms a seat with the inlet which prevents flow of fluid upwardly through the drill pipe but permits fluid to be pumped down the drill pipe and into the subjacent percussion motor. The valve stem, which forms a plunger 15 in cylinder 16, is urged upwardly so that the valve is normally in a closed position by a compression spring of the separator. The dense component then flows downwardly along the separator wall and into the circumferential trough 22 and the lighter component flows downwardly at the center of the separator. This dense component, which is usually liquid and/or solid, flows along radial troughs 23 in the top of radial ribs 24 into the top The whirler vanes of a motor bypass conduit 25 to the motor exhaust port 26 and thence through the drill bit ports (not shown) out into the well and are circulated to the surface in the well annulus with the drill bit cuttings. The lighter component of the drilling fluid, e.g., the clean gas, flows downwardly through the central openings 27 between the radial ribs 24 in the motor head 28. This drilling fluid then passes downwardly through the axial opening 29 in the annular free-piston-type hammer 30 which reciprocates longitudinally in housing 31. The hammer forms a fluid seal with the concentric bypass conduit 25 so that the power fluid passes through the port 32 in the lower end of the hammer and builds up pressure'underneath the hammer striking face 33 to lift the hammer from its bottom position, as shown, to its upper position.- As the hammer moves up, the upper finger valve 34 closes the opening 29 in the upper end of the hammer and substantially simultaneously opens the lower finger valve 35 to exhaust the high pressure gas from beneath the hammer striking face 33. During this return stroke of the hammer, the fluid in the annular recess 36 is displaced through port 37 and intermingled with the exhaust from the motor in the exhaust port 26. The amount of power fluid passing through the motor per cycle depends upon the internal volume of the hammer less the volume of the bypass tube within the hammer, i.e., the volume of chamber 38. This volume may be varied to change the operating characteristics, i.e., the frequency of the hammer by varying the internal diameter of either the opening or the bypass conduit. A preferred means involves placing an enlargement 39 on the motor bypass conduit 25. The outside diameter of the enlargement is less than the diameter of opening 29.

A variable volume chamber 41 for controlling the position of valve member 13 is formed by the plunger 15 in cylinder 16. The connection between the plunger and the valve member or dart is such that the volume of this I through the motor bypass conduit 25 to equalize the pressure within the variable volume chamber with the motor exhaust pressure or some pressure lower than the motor inlet pressure. The valve is thus held open by the differential pressure which exists between the inlet pressure acting downwardly on the plunger 15 and the motor ex- 7 I haust pressure which acts upwardly on the plunger. That is, the valve is not only held open by the flow of fluid when fluid is moving downwardly to the motor, but is held open by the pressure drop of the drilling fluid as it passes through and gives up its energy to the percussion motor. We have found that whereas customary drill pipe float valves are closed cyclically on the return cycle of the hammer when the flow of power fluid is temporarily halted, in a check valve actuated by the differential pressure across the motor the valve is held open continuously while the motor is'operating. When the motor is stopped, the pressure differential across the motordecreases rapidly, and in many cases even reverses, closing valve 13 rapidly and preventing the contaminated drilling fluid from backing up into the percussion motor.

On the return stroke, after the hammer is raised to a point at which the upper finger valve closes the opening 29 in the upper end of the hammer, the inertia of the hammer carries it up around the uppper finger valvefor a distance suflicient to open the lower valve 35 and exhaust the high prmsure gas within the hammer and between the hammer and the upper face 43 of the anvil 44. hausted, i.e., reduced to bottom hole pressure, the pressure of the drilling fluid on-the upper annular area 45of the hammer then forces the hammer down onthe power stroke at rapid rate causing it to strike the anvil at high With the-highpressure gas in the hammer exvelocity and produce an impact on the drill bit 12 which is attached to the lower end of the anvil. The anvil is held in the lower end of the housing 31 by a number of retaining balls 46 which are inserted through an opening 47 in the housing and lodged midway between the housing and the anvil with one-half in the wide groove 48 on the anvil and with the other half in the circumferential, semi-circular groove 49 within the housing. When the bottom 51 of the housing rests on the shoulder 52 of the drill bit, the balls are in the bottom of the elongated groove 48. When the drill pipe is raised, the anvil drops until the upper shoulder 53 strikes the balls 46 so that the anvil and bit can be recovered or lifted with the drill pipe. This provides a flexible longitudinal connection between the housing and the anvil so that when the hammer strikes the anvil, the impact is not transmitted to the housing. Mating splines 54 on the anvil and housing transmit torsional force from the drill pipe and housing 31 to the drill bit so that the bit can be rotated during vibratory drilling.

From the foregoing, it can be seen that we have provided an apparatus whereby power or drilling fluid contaminants, particularly liquids and solids in a gaseous drilling fluid, can be removed from the component of that drilling fluid which passes through a percussion motor at the lower end of the drill pipe and that by this means, the operating life of the motor components can be substantially extended. It will also be apparent that Whereas in this description reference has been made to a preferred embodiment, the invention should not be construed to be limited to that embodiment, but should instead be construed to be limited only by the scope of the appended claims.

We claim:

1. In a percussion drilling apparatus which includes a vibratory fluid actuated motor with fluid inlet and exhaust the improvement comprising a phase separator in the fluid inlet to said motor for separating and collecting a dense component from the power fluid flowing to said motor, a motor bypass conduit extending from said phase separator through said motor to the exhaust of said motor for carrying said dense component around said motor, a unidirectional valve having a valve member in the fluid inlet to said motor adapted to admit said power fluid to said motor, means fixed to said valve member and to said motor which forms a variable volume chamber that expands when said valve closes, and a pressure equalizing conduit extending from said variable volume chamber into said motor bypass conduit.

2. In a percussion drilling apparatus which includes a fluid actuated motor with fluid inlet and exhaust the improvement comprising a phase separator in the fluid inlet to said motor for separating and collecting a dense component from the power fluid flowing to said motor, and a bypass conduit extending from said phase separator to the exhaust port of said motor for carrying said dense component around said motor.

3. A percussion drilling apparatus for attachment to the lower end of a drill pipe comprising a vibratory fluid actuated motor with fluid inlet and exhaust having a tubular housing and an annular hammer adapted to oscillate longitudinally within said housing, a phase separator in the fluid inlet to said motor for separating and collecting a dense component from the power fluid flowing to said motor, a bypass conduit extending from said phase separator through said annular hammer to the exhaust port of said motor for carrying said dense component through said motor, a unidirectional valve having a valve member between said drill pipe and said motor adapted to admit power fluid to said motor, means fixed to said valve member and to said housing which forms a variable volume chamber that expands when said valve closes, and a pressure equalizing conduit extending from said variable volume chamber into said bypass conduit.

4. A percussion drilling apparatus including a vibratory fluid actuated motor with fluid inlet andexhaust, a unidirectional valve including a valve member in the fluid inlet to said motor and adapted to admit power fluid to said motor, means including a cylinder attached to the housing of said motor and a plunger which together form a variable volume chamber, means to connect said plunger to said valve member so that the volume of said chamber decreases as said valve opens, a phase separator in the fluid inlet to said motor for separating and collecting a dense component from said power fluid flowing to said motor, a bypass conduit extending from said phase separator through said motor to the exhaust port of said motor for carrying said dense component around said motor, and a pressure equalizing tube extending from said chamber down into said conduit to provide a differential pressure across said plunger for holding said valve open when said motor is operating.

5. A percussion drilling apparatus including a vibratory fluid actuated motor with fluid inlet and exhaust, a phase separator in the fluid inlet to said motor for separating and collecting a dense component from said power fluid flowing to said motor, a bypass conduit extending from said phase separator through said motor to the exhaust port of said motor for carrying said dense component around said motor, a check valve including a valve member in the fluid inlet of said motor to admit power fluid to said motor but prevent reverse flow therethrough, a cylinder attached to the housing of said motor and extending from said fluid inlet into said bypass conductor, a plunger in said cylinder, and means to connect said plunger to said valve member so that when said motor is operating the differential pressure across said plun er holds said valve open.

6. A percussion drilling apparatus comprising a vibratory fluid actuated motor with fluid inlet and exhaust having a tubular housing and an annular hammer adapted to oscillate longitudinally within said housing, a phase separator in the fluid inlet to said motor for separating and collecting a dense component from the power fluid flowing to said motor, and a bypass conduit extending from said phase separator through said annular hammer to the exhaust port of said motor for carrying said dense component through said motor.

7. A percussion drilling apparatus comprising .a vibratory fluid actuated motor with fluid inlet and exhaust having a tubular housing and an annular hammer adapted to oscillate longitudinally within said housing, a phase separator in the fluid inlet to said motor for separating and collecting a dense component from the power fluid flowing to said motor, a bypass conduit extending from said phase separator through said annular hammer to the exhaust port of said motor for carrying said dense component through said motor, a float valve including an upwardly closing valve member in said fluid inlet, a cylinder attached to said housing and extending from said fluid inlet into said bypass conduit, a plunger in said cylinder, and means to connect said plunger to said valve member so that when said motor is operating the differential pressure across said plunger holds said valve open.

8. A rotary-percussion drilling apparatus including a drill pipe, 21 fluid actuated percussion motor with fluid inlet and exhaust having a tubular housing connected to the lower end of said drill pipe, an annular hammer adapted to oscillate longitudinally within said housing, a phase separator between said motor and said drill pipe for separating and collecting a dense component from the power fluid flowing to said motor through said drill pipe, a bypass conduit extending from said phase separator through said annular hammer to the exhaust port of said motor for carrying said dense component through said motor, a drill pipe float valve having an upwardly closing valve member at the upper end of said phase separator, said float valve being adapted to admit said power fluid flowing down said drill pipe to said motor, means including said valve member forming a variable volume chamber which is attached to said housing, the

volume of said chamber being decreased when said valve opens and being increased when said valve closes, a pressure equalizing conduit connected at the upper end to said chamber and passing down through said bypass conduit to said exhaust port for equalizing the pressure in said chamber with the pressure in said exhaust port whereby said valve is held open when said pressure fluid is flowing downwardly through said drill pipe and said motor is operating, an anvil at the lower end of said housing, spline means to rotate said anvil with said housing, retainer means to connect said anvil loosely to said housing, and a drill bit connected to the lower end of said anvil.

References Cited in the file of this patent UNITED STATES PATENTS 

